A Das2Server is a data server introduced by the Radio and Plasma Wave Group (RPWG) at the University of Iowa in 2002. The server is still actively used for missions there, serving mostly time series parameters and spectrograms, and spectrograms that contain sampling mode changes. This is still unusual, and it uses custom "Das2Streams" to communicate data with mode changes. (QStreams were introduced to subsume this functionality, but both are still used.) Another central feature to Das2Servers is their server-side data reduction. The server typically sends over data at near pixel resolution, so the scientist can quickly get an overview of the data and zoom in to a region of interest. (Note reduction is done in the time dimension, and there have been proposals for how this would be supported in multiple dimensions.)

Autoplot supports Das2Servers, and is central to data analysis in the RPWG and other groups. This data source supports discovery, so when the name of a Das2Server is known one can query the server for available data sets.

At the top of the dialog is a droplist of known Das2Servers. Select a server from this list and the list below shows the data it contains is shown. Any Das2Server can be accessed here, just enter its URL into the editable droplist. Once data has been plotted from a server and the URI is in the scientist's history (autoplot_data/bookmarks/history.txt), the Das2Server will appear on the list of known servers.

The "Reader Parameters" area is a text box which can contain special parameters for the server. The server initializes a "Reader" to access the data and calculate a data response, and parameters here are passed into the Reader. The "View DSDF" button will give some information about the parameters the reader accepts. Note a transaction for describing the reader parameters has been planned for a while, and presumably at some time this dialog may become a GUI control panel.

"Force Intrinsic Resolution" will tell the server to send over all data within the interval, and no server-side reduction is done. "Sampling Interval" is used for some readers which can calculate their data at any resolution. These are typically ephemerides (parameters describing position, such as Lat, Long, and L-Shell) which are calculated on the server by SPICE kernals. Typically 60 seconds works fine when the orbits are many hours long. "TCA Item" can be used to select one of a set of parameters to access. For example, for ephemeris (a.k.a. TCAs), a set of useful parameters is sent over to annotate each tick of the x-axis. You can select one of these parameters for plotting with this droplist. When it does not show the names of the parameters, the parameter can be selected by index.